<?php

declare(strict_types=1);

namespace app\common\service\gancao;

/**
 * 甘草开放平台网关传输（AES-128-ECB + HTTP 头），对齐官方 GcOpenApi.php。
 */
final class GancaoOpenApiTransport
{
    private string $url;

    private string $ak;

    private string $sk;

    private string $userAgent;

    public function __construct(string $url, string $ak, string $sk, string $userAgent = 'zyt-admin/1.0')
    {
        $this->url = rtrim($url, '/');
        $this->ak = $ak;
        $this->sk = $sk;
        $this->userAgent = $userAgent;
    }

    /**
     * @param array<string,mixed> $payload 已含 package、class 及业务字段
     * @return array{state:int,msg:string,body?:array<string,mixed>,response?:string}
     */
    public function post(array $payload): array
    {
        // 与甘草网关规范一致：签名/头里的时间戳须与 body 内业务字段 timestamp（若有）一致，避免跨秒不一致导致签名校验失败
        $sigTs = time();
        if (isset($payload['timestamp']) && is_numeric($payload['timestamp'])) {
            $sigTs = (int) $payload['timestamp'];
        }
        if ($sigTs <= 0) {
            $sigTs = time();
        }
        $json = json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
        if ($json === false) {
            return ['state' => 0, 'msg' => 'json_encode 失败'];
        }
        $noise = self::randStr(8);
        $signature = sha1($json . $sigTs . $noise . $this->sk);
        $cipher = self::encrypt($json, $this->sk);
        if ($cipher === '') {
            return ['state' => 0, 'msg' => 'AES 加密失败'];
        }

        $headers = [
            'Connection: close',
            'Content-Type: application/json; charset=utf-8',
            'Content-length: ' . strlen($cipher),
            'Cache-Control: no-cache',
            'AK: ' . $this->ak,
            'Signature: ' . $signature,
            'UTC-Timestamp: ' . $sigTs,
            'NOISE: ' . $noise,
            'Expect:',
        ];

        // cURL 常量在部分精简构建里可能未注册，统一用 defined() 做优雅降级，值取自官方枚举
        $httpVer11 = defined('CURL_HTTP_VERSION_1_1') ? CURL_HTTP_VERSION_1_1 : 2;
        $ipv4Only = defined('CURL_IPRESOLVE_V4') ? CURL_IPRESOLVE_V4 : 1;

        $ch = curl_init($this->url);
        curl_setopt($ch, CURLOPT_HTTP_VERSION, $httpVer11);  // 改用 HTTP/1.1
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
        curl_setopt($ch, CURLOPT_USERAGENT, $this->userAgent);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_ENCODING, 'gzip');
        curl_setopt($ch, CURLOPT_IPRESOLVE, $ipv4Only);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);  // 增加连接超时
        curl_setopt($ch, CURLOPT_TIMEOUT, 120);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $cipher);
        curl_setopt($ch, CURLOPT_HEADER, true);
        if (str_starts_with($this->url, 'https:')) {
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
            curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);  // 改为 0，完全禁用主机验证
            // 强制 TLS 1.2；常量值为 6，但部分 PHP/cURL 构建未注册该常量，运行时未定义时退化为默认 TLS
            $tls12 = defined('CURL_SSLVERSION_TLSv1_2') ? CURL_SSLVERSION_TLSv1_2 : 6;
            curl_setopt($ch, CURLOPT_SSLVERSION, $tls12);
            // 可选 cipher list。默认不设（交给 cURL 自带默认，兼容性最好）。
            // 需要兼容弱加密服务器时，在 config/gancao_scm.php 或 .env 里设：
            //   GANCAO_SCM_TLS_CIPHERS="DEFAULT@SECLEVEL=1"  // 仅 OpenSSL 构建的 cURL 支持此语法
            //   GANCAO_SCM_TLS_CIPHERS="DEFAULT:!aNULL:!eNULL"  // 通用写法
            // cURL 是 LibreSSL/NSS/GnuTLS/BoringSSL 时，@SECLEVEL= 会直接报 CURLE_SSL_CIPHER(59)。
            $cipherList = trim((string) \think\facade\Config::get('gancao_scm.tls_ciphers', ''));
            if ($cipherList !== '') {
                curl_setopt($ch, CURLOPT_SSL_CIPHER_LIST, $cipherList);
            }
        }
        // 添加 TCP keepalive（部分旧 libcurl 可能没注册 CURLOPT_TCP_KEEPALIVE，守一下）
        if (defined('CURLOPT_TCP_KEEPALIVE')) {
            curl_setopt($ch, CURLOPT_TCP_KEEPALIVE, 1);
            curl_setopt($ch, CURLOPT_TCP_KEEPIDLE, 120);
            curl_setopt($ch, CURLOPT_TCP_KEEPINTVL, 60);
        }

        $raw = curl_exec($ch);
        $info = curl_getinfo($ch);
        $curlErr = curl_errno($ch);
        $curlMsg = curl_error($ch);
        curl_close($ch);

        if ($raw === false || (int) ($info['http_code'] ?? 0) !== 200) {
            $http = (int) ($info['http_code'] ?? 0);
            $err = is_string($raw) ? $raw : '';

            return [
                'state' => 0,
                'msg' => '通信失败：HTTP ' . $http . ($curlErr !== 0 ? ' curl#' . $curlErr . ' ' . $curlMsg : ''),
                'response' => $err,
            ];
        }

        $bodyRaw = substr($raw, strpos($raw, "\r\n\r\n") + 4);
        $plain = self::decrypt($bodyRaw, $this->sk);
        if ($plain === '') {
            $maybeJson = json_decode($bodyRaw, true);
            if (is_array($maybeJson) && isset($maybeJson['status'])) {
                return ['state' => 1, 'msg' => '成功(明文)', 'body' => $maybeJson];
            }

            return ['state' => -1, 'msg' => '解密失败（请核对网关 SK 是否为 16 位且与 AK 匹配）', 'response' => mb_substr($bodyRaw, 0, 500)];
        }

        $decoded = json_decode($plain, true);

        return ['state' => 1, 'msg' => '成功', 'body' => is_array($decoded) ? $decoded : []];
    }

    private static function encrypt(string $string, string $key): string
    {
        $out = openssl_encrypt($string, 'AES-128-ECB', $key, OPENSSL_RAW_DATA);

        return $out !== false ? base64_encode($out) : '';
    }

    private static function decrypt(string $string, string $key): string
    {
        $bin = base64_decode($string, true);
        if ($bin === false) {
            return '';
        }
        $out = openssl_decrypt($bin, 'AES-128-ECB', $key, OPENSSL_RAW_DATA);

        return $out !== false ? $out : '';
    }

    private static function randStr(int $length = 8): string
    {
        $chars = 'ABCDEFGHIJKLMNPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890';
        $chars = str_shuffle($chars);
        $end = strlen($chars) - 1;
        $buf = [];
        while (true) {
            $c = $chars[random_int(0, $end)];
            if ($c !== '0') {
                $buf[] = $c;
                break;
            }
        }
        $n = 1;
        while ($n < $length) {
            $r = $chars[random_int(0, $end)];
            if ($r !== $buf[count($buf) - 1]) {
                $buf[] = $r;
                ++$n;
            }
        }

        return implode('', $buf);
    }
}